The invention relates to a device a device for treating work pieces with an explosive gas mixture. In particular to a thermic deburring device. In such devices for thermic deburring of work pieces an unaimed removal occurs, whereby the total work piece is subjected to a heat shock. Preferably, corners and edges are removed since these locations absorb a lot of heat with a large surface and a small volume and are therefore oxidized or burned. The heat shock is generated by burning off a combustion gas-oxygen-mixture, whereby hydrogen, natural gas or methane is used as a combustible gas. The gas components are fed from a supply into one each dosaging cylinder and are pumped by means of a compressor under a considerable compression through valves into the work piece finishing chamber, whereby their admixing occurs in a mixing chamber. The compression of the gas components is uniformly large and corresponds towards the end of the filling in the work-piece finishing chamber to the pressure which is required for the given optimum combustion operation. The higher the combustion gas-oxygen-mixture has been compressed, the higher is the energy and the more severe is the deburring effect. The combustion temperature of the gas is in a range of 2500.degree. C. to 3500.degree. C. The heat amount released increases per volume unit with the increase of the pressure. The pressures generated in the work piece finishing chamber are about 40 bar when filling the chamber. During the explosion shortly after the ignition a pressure of about 700 bar is generated in the chamber. This short lived very high pressure stresses the construction parts of the mixing chamber which are connected to the work piece finishing chamber.
In a known device the mixing chamber is flanged onto the work piece finishing chamber as a structural part and contains, among other things a spark plug required for igniting the gas mixture. When igniting the gas mixture the explosion advances from the area of the spark plug in direction of the work piece finishing chamber. In the view of the high explosion pressure and the high combustion temperatures in the work piece finishing chamber the immediately connected mixing chamber is also subjected to very high stresses. In particular, a rapid contamination of the spark plug occurs which may result in a breakdown of the deburring device which operates in a cycle.
In order to avoid this a gas deceleration stage was mounted between the work piece finishing chamber and the gas mixing chamber with labyrinth or meander like extending lines. Thereby, the contaminations generated by the combustion pressure wave during deburring of work pieces in the work piece finishing chamber cannot reach the mixing chamber, but are caught in the lines of the gas deceleration stage.
In the known device the work piece finishing chamber, the gas mixing chamber and the gas deceleration stage are shaped as different blocks being flanged together. The material and manufacturing costs for these blocks are considerable, so that the purchase price of such an installation is rather high.